Goodbye Kansas

[kevins2]

Originally Posted by ERA2076

Elevation adjuster tool

Well, so much for Craftman's lifetime warranty

[a427sc]

Not exactly your #'s but have the 125# split F/R. Would be a softer option, and the price might work for you. Cheap enough to play with.

Set of coilover springs for an ERA 427 (or other car, your decision) for a Competition/Open Track setup with Spax or similar type shocks.

2 Front 10"x400# AFCOIL also-2 Eibach 10"x350#
4 Jag Rear 8"x525# AFCOIL

$200 for all 8 or BO. Reply @ a427sc@aol.com

[ERA2076]

Thanks for the offer, but I am committed to the Penskes .Double adjustable and I can run the bodies on top.

chr

[a427sc]

.......

[ERA2076]

The reason I am fixated on the roll is the roll centers do not move well together front to rear. The short front control arms have the front roll center moving laterally 7" at 1 degree of roll, where the back moves only 1/2" because the control arms are longer. In "Tune to Win" Smith states he thought control of the roll centers was more important than maximizing the camber curves because it affects how the car rotates especially at turn in. The front shocks were valved for 350lb springs but I know there is some float there. I am going to run the heaviest spring I can up to 450 in the front. Then match the appropriate rear spring and have the rears valved for that. It is a place to start.

chr

[ERA2076]

https://www.youtube.com/watch?featur...&v=sSlayk9j4FE

[strictlypersonl]

Lateral movement of the roll centers is an inherent characteristic of a short-long-arm design. The basic ERA intent is to keep the outer roll center fairly close to the ground so that there is minimal laterally-induced instability on the outer tire under cornering loads.

[ERA2076]

Bob - I read this as you want to control jacking.

Trivia -

If one believes the car rolls around the geometric roll centers; at 3 degrees of roll, the front has moved laterally 20 inches (still inside the ball joint) and the rear has moved 1.5. Our roll axis is now at a significant angle (in plan) to the mass centroid line which does not intuitively seem like a good thing to me.

If I did not want to run it so bad, I would seriously look at moving the front inner pivots inboard .5 inch and lengthening the arms accordingly.

.5 inches cause it looks like it could be done and it would cut the difference by half.



chr

[Bobcat]

Bob ... does this also mean that keeping the lower control arms as level/parallel to the ground is more important to handling than lowering the front and changing the roll centers ??

Bob

[ERA2076]

It is in my world. Lower it and the roll moment increases. Raise it and jacking is increased. Raise it or lower it and the camber curve is more aggressive which could or could not be beneficial. Putting them parallel is a good compromise. A rule of thumb is to run the longest virtual swing arm you can. One would have to test if raising or lowering the roll centers would be of benefit. i.e. the car is quicker with more roll as opposed to more jacking and the reverse. With mine set parallel the front is 1.2 off the ground and the rear is 1.9. It seems one would opt for lowering and controlling the roll with bars or springs provided it did not ruin the camber curve and or mechanical grip.

I can't see how adding jacking could ever be good which is why I never opt to raise them beyond parallel to the ground. That said, the 26.5 tires have not helped me

chr

[strictlypersonl]

Originally Posted by ERA2076

... A rule of thumb is to run the longest virtual swing arm you can...
chr

When we first started out, we did tire testing with BF Goodrich. (Back then the CompTA was the hot tire.) It was their recommendation that we shorten the virtual swing arm length in order to increase the camber gain. Street tires haven't changed that much since then. We're still using the same sizes and profiles in 15" sizes. The profile of 17" wheels is somewhat different, but the tires still require some camber correction on roll.

Formula cars are different. Roll is negligible and tires are very wide. For them, roll compensation is neither necessary nor desirable.

On our cars, you could run a lot of negative camber, but that has negative consequences on tire wear and loss of traction of the inside tire. We're still better off with the compromise of some partial camber gain on roll.

Or you could put in springs so stiff that roll would be near zero, and bounce down the road from hump to bump.

[strictlypersonl]

Anti-sway bars are wonderful, but there are limitations. For one thing, they don't reduce squat or lifting under power. Secondly, when one tire hits a bump, it transfers some of the force to the other tire. Everything is a compromise unless you go to a very sophisticated electronic control system that is much smarter than we are.

[ERA2076]

nah - lot's and lot's of great performance cars have been built with old school tech. The last thing I would ever want is some kind of active suspended Cobra.

chr

[ERA2076]

Chas - we have been open tracking the Mustang and it has been getting all of the attention. The FIA got pushed to the back of the shop. I hope to get it back on the rack tomorrow. I ordered the rear wheels a couple of months ago but have not seen them yet. I was close to ordering the fronts but needed to check clearances one moer time and Bill pulled the car before I could get it done.

Some pics and a vid -

The air dam cracked so we rebuilt it with UHMW


Splitter and dam are riveted together. Dzus and nut inserts to attach to car.


Welded in a subframe and integrated with a roll bar. Spot welded the body pinch weld to a jacking rail and tied jacking rail to subframe connector.

Tied the roll bar to the rear shock tower brace. Seats are FIA approved and we finally went to belts. What a treat.

We did not reinstall the interior. Bent up some aluminum to cover the tunnel wiring and used some builder parts from Jegs for the boot. Riveted ABS to the floor.


Boxed jacking pads


The car has had CO since new 375/550. With the added Aero it was getting to the point I was over driving it and it was getting very frustrating. I called Maximum Motorsports and they set me up with 525/700 springs and dampers and 3 degree camber, 1/32/ toe out, and 6.5 degree caster of which we could not obtain. We just tried to get as much as we could 2.5, 1/32, 4.5 and it is an absolute blast to drive. There is some left but I need a new K member to optimize the front geometry.

I don't have the whole GoPro thing worked out so skip forward to around 5 min and you can see it run. Shift light is set at 6100 rpm.

The yellow Lotus is the first target for the FIA. If we cannot get him I will be bummed. He has much newer technology and some of the best engineering in the world. - I am counting on being able to control the FIA to 7000 - set shift light at 7100. We will have gobs more HP just hope we can use it.

[ame="https://www.youtube.com/watch?v=1NG_YWQEp0Q"]https://www.youtube.com/watch?v=1NG_YWQEp0Q[/ame]

It just takes a lot of time but there is no way to get to the FIA w/o going thru the Mustang. I did get signed off to drive solo with Pro Drive. I have been driving solo with some of the clubs, but it was gratifying get signed off by a PD instructor.

We are going to try to have the FIA running by the end of summer. I am searching for some kind of a skid pad so we can test and tune some before we put it on a track. I am excited and a little nervous about tracking the FIA. The thing should be very fast - The Mustang weighs 3500 wet. Trying to get the FIA to 2315 race. The FIA has more HP than the SVT.

Such a short wheel base.

[ERA2076]

Rears finally came in - beautiful. Every non machined surface powder coated. Steel inserts for the studs to pass thru.



My biggest fear turned out to be nothing. There is plenty of room for the caliper. They are almost a cylinder with nothing more than a slight taper as you move outboard.




Heavier than I would like (24 lb) but a full 10".





I talked to Roger Kruas Racing about running the CR6ZZ on the FIA.

(-) 1.5 degrees camber front, (-) 1 degree rear.

Less (or is that more ) than I expected on the front.

[blykins]

Get that engine lit off!

[RRRuiz]

Wow, nice separation of the pedals. Real nice set up.

[ERA2076]

Originally Posted by RRRuiz

Wow, nice separation of the pedals. Real nice set up.

Thanks - it seems like short people would fit well - me - not so good.

chr

[ERA2076]

Can one of you ERA guy's advise me. We are working on final assembly of the rear into the car. The manual says to set the lower trailing link to 16.5". This causes all kinds of fitment issues for us, such as the rear radius arm inner pivot is reward past the mounting tabs on the cradle thus putting a bending moment in the link if we try to assemble.

15.5 " and it all goes together pretty smoothly and looks correct i.e. anti-squat at cradle, visually looks reasonable with anti-squat at lower edge of upright.

I need to make sure because of the relationship to the upper trailing link as well as several others.

I checked the latest manual and it too calls for 16.5"

What am I missing?

x-chr

[DanEC]

I see 16 inches in the 427 manual for the trailing arms. A couple of us ran into a little interference between the tire and the front of the wheel well and Doug advised extending the trailing arm link a little to swing the suspension assembly rearward slightly more, providing more clearance. I don't think a precise dimension for the trailing arm adjustment is critical to anything as long as the suspensions and tires cycle without issue and it's equal on both sides. But a quick call to Doug should get you an answer.